House Speaker Nancy Pelosi is arguably the least popular Democrat in Washington, according to a new CNN poll.

Washington (CNN) - A new national poll indicates that slightly more than half of all Americans have an unfavorable view of House Speaker Nancy Pelosi, a finding that may make her the most unpopular Democrat in Washington nowadays.

But according to the CNN/Opinion Research Corporation survey released Wednesday, House Minority Leader John Boehner, the man trying to replace Pelosi as speaker, doesn't fare particularly well among the minority of Americans who have an opinion of him.

Fifty-one percent of people questioned in the poll say they have an unfavorable view of Pelosi, with 33 percent saying they see her in a favorable light, and 16 percent unsure. The California Democrat's unfavorable rating has climbed from 23 percent in 2006 to 43 percent last year and 50 percent at the beginning of 2010.

"Pelosi's unfavorable rating hit 50 percent at the start of this year and has stayed there throughout the spring and summer. That arguably makes her the least popular Democrat in the country," says CNN Polling Director Keating Holland.

According to the survey, 22 percent of the public has a favorable opinion of Boehner, with 23 percent saying they hold an unfavorable view of the Republican congressman from Ohio.

It's pretty much the same story on the other side of Capitol Hill, where just under one in four Americans have a favorable opinion of Senate Majority Leader Harry Reid, with 37 percent saying they see the Nevada Democrat in an unfavorable light. Twenty-six percent say they have a favorable opinion of Senate Minority Leader Mitch McConnell, with 24 percent saying they hold an unfavorable view of the Kentucky Republican

"Most Americans, of course, aren't very familiar with congressional leaders. Nearly four in ten don't have an opinion of Reid, and Boehner and McConnell are unknown to at least half of all Americans," adds Holland. "The exception is Pelosi, who has become less popular as more Americans became familiar with her."

President Barack Obama's unfavorable rating stands at 45 percent, up four points from April. But a majority - 53 percent - still say they see the president in a favorable light. The poll indicates Americans are divided on their view of Vice President Joe Biden, with 43 percent saying they view him favorably and an equal amount saying they hold a negative view of the vice president.

According to the survey, former Alaska Gov. Sarah Palin is popular with only 38 percent of all Americans, with 52 percent holding an unfavorable view of the 2008 GOP vice presidential nominee. Palin has been influential in the Republican primary process, but the jury's still out on her impact on the general election.

But the survey indicates that Obama's predecessor may have a negative impact on the midterms.

"Former President George W. Bush has a 53 percent unfavorable rating - one more reason why voters are likely to hear his name mentioned at every Democratic rally and virtually no Republican gatherings," adds Holland.

The CNN/Opinion Research Corporation poll was conducted September 1-2, with 1,024 adult Americans questioned by telephone. The survey's overall sampling error is plus or minus three percentage points.